Technologies for calibrating positional relations between cameras have been developed. For example, the technology disclosed in the following Patent Literature 1 can be exemplified as a technology for calibrating a positional relation between cameras by calculating a fundamental (F) matrix using a light-emitting sphere as a calibration jig. In addition, technologies for obtaining relative positions of a plurality of image sensors have been developed. For example, a technology disclosed in the following Patent Literature 2 can be exemplified as a technology for gaining a relative position of a plurality of image sensors on the basis of images obtained from the image sensors.